Brake band alignment

[Swinz]

I am having trouble setting up my brake band, after adjustment it keeps moving rearwards off the drum to the point it doesn't grip the drum and the pedal hits the floor. It worked fine until I removed the pedal to weld on an extension for the Rocky Mountain brakes that I'm fitting.
Any ideas what issues to look for? I'm thinking the steel band that the linings are riveted to could be twisted or out of shape, I have never had the bands out whilst I have owned the car so I don't know the condition of them. Relatively new to model T's so not sure if this is a common problem.

Paul.

[Scott_Conger]

Paul

pictures are all but mandatory to get you the help you need

[speedytinc]

Pictures, yes.
The band is held via the pedal shaft. It cant slip back @ the top at least(left hand drive?)

If RHD, may be a different matter. The band would still be held between the adjuster pin & pedal pin. (I believe a RHD brake pedal setup is like a LHD low pedal)

[Norman Kling]

Are you sure you got the shaft between the fork in the ears of the band? Also when you do this it is good to first put rags alongside the bands so nothing will accidently fall into the bottom of the transmission. Use a clamp or something to pull the ears close together and tie them in place with a strong string or wire. The spring should be between the bands. Then put the washer in the groove with the notch toward the nut and turn the nut to adjust. Both ends of the shaft should be between the fork of the ears of the band. Unless there is a very abnormal amount of wear on the shaft and the hole through which it goes, the shaft should not move front to back when you apply the brake. A picture through the inspection plate showing what it looks like when the band slips off would be very helpful.
Norm

[Norman Kling]

If you have right hand drive, disregard my suggestions. I have no experience with the right hand drive.
Norm

[Jerry VanOoteghem]

As everyone states, "pictures please". In the meanwhile, I'm wondering if your brake band is cracked, causing an uneven tension that's skewing the band off location. I'd also be suspicious of partially missing band lining.

[Swinz]

I'm afraid that I don't have any pictures at the moment but I will post some tomorrow when I am back home, the car is LHD and the band is held securely between the fork ears at the top and is coming off the drum at the bottom (6 o'clock position)

Paul

[Craig Leach]

Hi Paul,
Assuming you dont have a 26-27 hogshead on a early trans. (short drum) I would think the only way that can happen is if the band is to loose
( adjustment) or there is no lining on the bottom of the band. This will let the band swing back. Could there be something wrong with low band?
Craig.

[JTT3]

Paul, pictures would definitely help however are you sure it’s the metal band or the band material. If the latter you’ve probably lost some rivets on the bottom or worse yet the material has rotted. Luckily it’s the brake band easier to reline or re-rivet. Just re read your posts again. You said you’re relatively new to T’s & you’ve never changed the material, the brake is the most used band so it may be time to replace unless you have Kevlar bands. Have you tried pushing down on the material with a long flat screwdriver to see if it’s actually still attached to the metal band? Just a few suggestions.

[Jerry VanOoteghem]

Excellent thought John!

[Swinz]

Here are some photos of the inside of my transmission, I placed the band central to the brake drum and adjusted it so that the pedal stopped about an inch from the floor. I them pressed the pedal a few times and the band slowly moved rearwards with every press until it moved enough off the drum for the pedal to hit the floor. Looking at the bolt and lock wire I would say that it has been running in this position for a while.

[speedytinc]

Not necessarily pertinent to your problem, but it appears you have a late(26-7) output plate on an earlier narrow drum. The output plate edge becomes part of the brake drum surface. There should be no gap between the drum & plate. As is, you potential have 2 razor edges cutting your lining.
That situation may be cutting & wearing out your band material.(likely) I do believe you have the correct HH to match the narrow brake drum.

To that point, judging by your return spring, your band lining is worn out . Needs replacing.
The shifting band may be caused by loose material on the band as described earlier. With a relatively round band & properly attached lining & tightened, the band hasnt the room to run off until severe slack takes place from wear in the band material.

[Scott_Conger]

I suspect that removal/replacement of the brake pedal is a red herring.

the band material looks THICK! and yet the band is adjusted as though it is worn out. I pondered about the pedal suddenly going to the floor along with the band material pooching to the rear and I really wonder if perhaps the steel band is not fractured and the friction material is now free to wander

And I agree with John regarding the output plate info he gave you

[speedytinc]

The fractured band theory is a strong one. Its quite common to find bands with the beginnings of a crack @ the lower rivet tab on a demountable band.
It should not be repaired. The band should be replaced. Welding the crack up typically insures its eventual total failure.
I have experienced a brake band complete break. Going down a mountain highway on a newly (hours earlier) purchased T. Fortunately the 27 big drum parking brake was just dry enough to eventually stop the car.
Anyway if you tighten the band & it loses its setting quickly, it may well be the lining is stretching & the only thing holding the band in place for now.
Either way the next step is to pull the band.
If you do replace the band & lining, get in there & file down the 2 sharp edges @ the back of the drum to minimize the lining damage untill you get around to tearing things down to replace the drive plate. I would use a tough lining like the scandinavia "tar baby" in the mean time.

[Kerry]

The whole thing looks to be a cock up, trying to marry up a 26/7 drive plate to an earlier drum will never run true, the outside diameter of the plate is smaller, the bolt up pattern is way off, it must have had the crap filed out of the holes to sort of fit.

[Mark Gregush]

Does the hogs head have the ear where it would mount to the block?

[Kerry]

Mark, the spacing of the shafts shows it to be pre 26.

[Swinz]

I have taken my transmission apart to try and solve the issue with my brake band, hopefully someone can advise me on what I have and the best way forward, I believe my drum is a wide drum which has been machined in to a narrow drum but then they have used the drive plate off the wide drum, can the narrow drive plate be made to work with a modified wide drum?

[speedytinc]

Your drum isnt necessarily a cut down wide drum. It looks like the late narrow replacement drum that did come with shoes. The drive plate would have the lip like the pre 25 plate, but with a slightly different bolt mounting pattern. That lip was actually part of the drum's lining surface.

[Jerry VanOoteghem]

Do you have a picture of the brake band itself? Have you closely inspected it for any cracks, including where the end lugs attach?

Your drum appears to be fine. You just need the proper drive plate. Is the outside diameter of the drum, (where the brake band rides), straight, and not tapered?

[Kerry]

OK, now it can be seen what has been done, the drum is an 1925 narrow band and fitted shoes, a rare drum, if it was a wide drum turned down, the number on it would be T-709-B The T-709 is the narrow drum number, The drive plate is a wide drum one that has had the bolt holes over sized to try and marry it to the drum, remedy is to find a small drum drive plate.